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Boeing 727
The Boeing 727 is a midsized, jet aircraft built by from the early 1960s to 1984. It can carry 149 to 189 passengers and later models can fly up to 2,700 (5,000 km) nonstop. Intended for and medium-length flights, the 727 can use relatively short runways at smaller airports. It has three engines below the , one on each side of the rear fuselage with a center engine that connects through an to an inlet at the base of the fin. The 727 is the only Boeing trijet, as a commercial design entering production. The 727 followed the , a quad-jet airliner, with which it shares its upper fuselage cross-section and cockpit design. The 727-100 first flew in February 1963 and entered service with in February 1964; the stretched 727-200 flew in July 1967 and entered service with that December. The 727 became a mainstay of airlines' networks and was also used on short- and medium-range international routes. Passenger, freighter, and convertible versions of the 727 were built. The highest production rate of the 727 was in the 1970s; the last 727 was completed in 1984. As of July 2018update, a total of 44 Boeing 727s (2× 727-100s and 42× -200s) were in commercial service with 23 airlines, plus a few more in government and private use. Airport have led to 727s being equipped with . Since 1964, there have been 118 fatal incidents involving the Boeing 727. Successor models include variants of the and the . Contents * ** * ** ** ** ** ** * ** * * * * * Development[] Production of the 727 Three-crew cockpit The Boeing 727 design was a compromise among , , and ; each of the three had developed requirements for a jet airliner to serve smaller cities with shorter runways and fewer passengers. United Airlines requested a four-engine aircraft for its flights to high-altitude airports, especially its hub at in . American Airlines, which was operating the four-engined and , requested a twin-engined aircraft for efficiency. Eastern Airlines wanted a third engine for its overwater flights to the Caribbean, since at that time twin-engine commercial flights were limited by regulations to routes with 60-minute maximum flying time to an airport (see ). Eventually, the three airlines agreed on a design for the new aircraft. In 1959, , chairman of (BEA), suggested that Boeing and (later ) work together on their trijet designs, the 727 and , respectively. The two designs had a similar layout, the 727 being slightly larger. At that time Boeing intended to use three AR963 turbofan engines, license-built versions of the used by the Trident. Boeing and de Havilland each sent engineers to the other company's locations to evaluate each other's designs, but Boeing eventually decided against the joint venture. De Havilland had wanted Boeing to license-build the D.H.121, while Boeing felt that the aircraft needed to be designed for the American market, with six-abreast seating and the ability to use runways as short as 4,500 feet (1,400 m). In 1960, was looking for a customer for its new turbofan design study, based on its turbojet, while United and Eastern were interested in a Pratt & Whitney alternative to the RB163 Spey. Once Pratt & Whitney agreed to go ahead with development of the JT8D, , chairman of the board of Eastern, told Boeing that the airline preferred the JT8D for its 727s. Boeing had not offered the JT8D, as it was about 1,000 lb (450 kg) heavier than the RB163, though slightly more powerful; the RB163 was also further along in development than the JT8D. Boeing reluctantly agreed to offer the JT8D as an option on the 727, and it later became the sole powerplant. With on its wing, the 727 could use shorter runways than most earlier jets (e.g. the 4800-ft runway at Key West). Later 727 models were stretched to carry more passengers and replaced earlier jet airliners such as the Boeing 707 and , as well as aging propeller airliners such as the , , , and the on short- and medium-haul routes. For over a decade, more 727s were built per year than any other jet airliner; in 1984, production ended with 1,832 built and 1,831 delivered, the highest total for any jet airliner until the surpassed it in the early 1990s. Design[] The 727 tail and rear airstairs The airliner's middle engine (engine 2) at the very rear of the fuselage gets air from an inlet ahead of the vertical fin through an . This S-duct proved to be troublesome in that flow distortion in the duct induced a surge in the centerline engine on the take-off of the first flight of the 727-100. This was fixed by the addition of several large in the inside of the first bend of the duct. six-abreast seating The 727 was designed for smaller airports, so independence from ground facilities was an important requirement. This led to one of the 727's most distinctive features: the built-in that opens from the rear underbelly of the fuselage, which initially could be opened in flight. Hijacker used this hatch when he parachuted from the back of a 727, as it was flying over the . Boeing subsequently modified the design with the so that the airstair could not be lowered in flight. Another innovation was the (APU), which allowed electrical and air-conditioning systems to run independently of a ground-based power supply, and without having to start one of the main engines. An unusual design feature is that the APU is mounted in a hole in the keel beam web, in the main bay. The 727 is equipped with a retractable tailskid that is designed to protect the aircraft in the event of an over- on takeoff. The 727's fuselage has an outer diameter of 148 inches (3.8 m). This allows six-abreast seating (three per side) and a single aisle when 18-inch (46 cm) wide coach-class seats are installed. An unusual feature of the fuselage is the 10-inch (25 cm) difference between the lower lobe forward and aft of the wing as the higher fuselage height of the center section was simply retained towards the rear. Nosewheel brakes were available as an option to reduce on landing, which provided reduction in braking distances of up to 150 m. The 727 proved to be such a reliable and versatile airliner that it came to form the core of many startup airlines' fleets. The 727 was successful with airlines worldwide partly because it could use smaller runways while still flying medium-range routes. This allowed airlines to carry passengers from cities with large populations, but smaller airports to worldwide tourist destinations. One of the features that gave the 727 its ability to land on shorter runways was its clean wing design. With no wing-mounted engines, leading-edge devices (Krueger, or hinged, flaps on the inner wing and extendable out to the wingtip) and trailing-edge lift enhancement equipment (triple-slotted, fowler ) could be used on the entire wing. Together, these high-lift devices produced a maximum wing lift coefficient of 3.0 (based on the flap-retracted wing area). The 727 was stable at very low speeds compared to other early jets, but some domestic carriers learned after review of various accidents that the 40-degree flap setting could result in a higher-than-desired sink rate or a stall on final approach. These carriers' Pilots' Operation Handbooks disallowed using more than 30° of flaps on the 727, even going so far as installing plates on the flap lever slot to prevent selection of more than 30° of flaps. Noise[] Stage three The 727 is one of the noisiest commercial jetliners, categorized as Stage 2 by the of 1972, which mandated the gradual introduction of quieter Stage 3 aircraft. The 727's jet engines use older technology, whereas Stage 3 aircraft use the more efficient and quieter design. When the Stage 3 requirement was being proposed, Boeing engineers analyzed the possibility of incorporating quieter engines on the 727. They determined that the JT8D-200 engine could be used on the two side-mounted pylons, but the structural changes to fit the larger-diameter engine (49.2 inches (125 cm) fan diameter in the JT8D-200 compared to 39.9 inches (101 cm) in the JT8D-7) into the fuselage at the engine location were prohibitive. Current regulations require that a 727 in commercial service must be with a to reduce engine noise to Stage 3 levels. One such hush kit is offered by , and has been purchased by over 60 customers. Aftermarket kits, originally developed by Valsan Partners and later marketed by Quiet Wing Corp. have been installed on many 727s to reduce noise at lower speeds, as well as to reduce fuel consumption. In addition, developed packages to enable 727s to meet the Stage 3 noise requirements. These packages managed to get light- and medium-weight 727s to meet Stage 3 with simple changes to the flap and slat schedules. For heavier-weight 727s, exhaust mixers must be added to meet Stage 3. American Airlines ordered and took delivery of 52 Raisbeck 727 Stage 3 systems. Other customers included TWA, Pan Am, Air Algérie, TAME, and many smaller airlines. Since September 1, 2010, 727 jetliners (including those with a hush kit) are banned from some Australian airports because they are too loud. Operational history[] A FedEx Express 727-233 departs In addition to domestic flights of medium range, the 727 was popular with international passenger airlines. The range of flights it could cover (and the additional safety added by the third engine) meant that the 727 proved efficient for short- to medium-range international flights in areas around the world. Prior to its introduction, four-engined jets or propeller-driven airliners were required for transoceanic service. The 727 also proved popular with cargo and charter airlines. introduced 727s in 1978. The 727s were the backbone of its fleet until the 2000s; FedEx began replacing them with in 2007. Many cargo airlines worldwide employ the 727 as a workhorse, since, as it is being phased out of U.S. domestic service because of noise regulations, it becomes available to overseas users in areas where such noise regulations have not yet been instituted. Charter airlines , , and all started with 727 aircraft. The 727 had some military uses, as well. Since the aft stair could be opened in flight, the Central Intelligence Agency used them to drop agents and supplies behind enemy lines in . The 727 has proven to be popular where the airline serves airports with gravel, or otherwise lightly improved, runways. The Canadian airline , for example, previously used a 727-100C to serve the communities of and in Nunavut, whose and former both have gravel runways. The high-mounted engines greatly reduce the risk of . According to the Boeing Jetliner Databook, the , also known as 'Con Air', currently uses four 727 aircraft to transport persons in legal custody between prisons, detention centers, courthouses, and other places. A military version, the Boeing C-22, was operated as a medium-range transport aircraft by the and to personnel. A total of three C-22Bs were in use, all assigned to the , . retired its last 727 in June 2003 At the start of the 21st century, the 727 remained in service with a few large airlines. Faced with higher fuel costs, lower passenger volumes due to the post- economic climate, increasing restrictions on airport noise, and the extra expenses of maintaining older planes and paying ' salaries, most major airlines phased out their 727s; they were replaced by , which are quieter and more fuel-efficient. Modern airliners also have a smaller flight deck crew of two pilots, while the 727 required two pilots and a flight engineer. , the last major U.S. carrier to do so, retired its last 727 from scheduled service in April 2003. retired its last 727 from charter service in June 2003. Many airlines replaced their 727s with either the or the ; both are close in size to the 727-200. As of July 2013update, a total of 109 Boeing 727s (5× 727-100s and 104× -200s) were in commercial service with 34 airlines; three years later, the total had fallen to 64 airframes (4× 727-100s and 60× -200s) with 26 airlines. was the last operator of scheduled Boeing 727 passenger flights, and flew the aircraft's final scheduled passenger service on January 13, 2019. On March 2, 2016, the first 727 produced (N7001U), which first flew on February 9, 1963, made a flight to a museum after extensive restoration. The 727-100 had carried about three million passengers during its years of service. Originally a prototype, it was later sold to United Airlines, which donated it to the in Seattle in 1991. The jet was restored over 25 years by the museum and was ferried from in Everett, Washington to in Seattle, where it was put on permanent display at the Aviation Pavilion. The Federal Aviation Administration granted the museum a special permit for the 15-minute flight. The museum's previous 727-223, tail number N874AA, was donated to the in Kansas City and will be flown to its new home once FAA ferry approval is granted. Variants[] Data from:''Boeing Aircraft since 1916 The two series of 727 are the initial 100 (originally only two figures as in −30), which was launched in 1960 and entered service in February 1964, and the 727-200 series, which was launched in 1965 and entered service in December 1967. 727-100[] Shorter 727-100, of The first 727-100 (N7001U) flew on February 9, 1963 and FAA type approval was awarded on December 24 of that year, with initial delivery to United Airlines on October 29, 1963, to allow pilot training to commence. The first 727 passenger service was flown by Eastern Air Lines on February 1, 1964, between Miami, Washington, DC, and Philadelphia. A total of 571 Boeing 727-00/100 series aircraft were delivered (407 -100s, 53 -100Cs, and 111 -100QCs), the last in October 1972. One 727-100 was retained by Boeing, bringing total production to 572. The −100 designation is a retroactive one to distinguish the original short-body version. Aircraft for United Airlines were delivered as 727-22, for American Airlines as 727-23, and so on — not -122 and -123 — and retained these designations even after the advent of the 727-200. ; 727-100C Convertible passenger cargo version, additional freight door and strengthened floor and floor beams, three alternative fits: * 94 mixed-class passengers * 52 mixed-class passengers and four cargo pallets (22,700 pounds; 10,300 kg) * Eight cargo pallets (38,000 pounds; 17,000 kg) ; 727-100QC QC stands for Quick Change. This is similar to the convertible version with a roller-bearing floor for palletised galley and seating and/or cargo to allow much faster changeover time (30 minutes). ; 727-100QF QF stands for Quiet Freighter. A cargo conversion for , these were re-engined with -compliant turbofans. ; Boeing C-22A : A single 727-30 acquired from the , it was originally delivered to . This aircraft served mostly with flying from / . ; Boeing C-22B : Four 727-35 aircraft were acquired from by the for transporting and National Guard personnel. 727-200[] Longer 727-200, of A stretched version of the 727-100, the -200 is 20 feet (6.1 m) longer (153 feet 2 inches;46.69 m) than the −100 (133 feet 2 inches;40.59 m). A 10-ft (3-m) fuselage section ("plug") was added in front of the wings and another 10-ft fuselage section was added behind them. The wing span and height remain the same on both the −100 and −200 (108 and 34 feet (33 and 10 m), respectively). The original 727-200 had the same maximum gross weight as the 727-100; however, as the aircraft evolved, a series of higher gross weights and more powerful engines was introduced along with other improvements, and from line number 881, 727-200s are dubbed −200 Advanced. The aircraft gross weight eventually increased from 169,000 to 209,500 pounds (76,700 to 95,000 kg) for the latest versions. The dorsal intake of the number-two engine was also redesigned to be round in shape, rather than oval as it was on the -100 series. The first 727-200 flew on July 27, 1967, and received FAA certification on November 30, 1967. The first delivery was made on December 14, 1967, to . A total of 310 727-200s were delivered before its place on the production line was taken over by the 727-200 Advanced in 1972. ; 727-200C A convertible passenger cargo version, only one was built. ; 727-200 Advanced The Advanced version of the 727-200 was introduced in 1970. More powerful engines, fuel capacity and MTOW (185,800 to 210,000 lb or 84.4 to 95.3 t) increased the range from 1,930 to 2,550 nmi (3,570 to 4,720 km) or by 32%. After the first delivery in mid-1972, Boeing eventually raised production to more than a hundred a year to meet demand by the late '70s. Of the passenger model of the 727-200 Advanced, a total of 935 were delivered, after which it had to give way to a new generation of aircraft. Freighter cargo hold ; 727-200F Advanced A freighter version of the 727-200 Advanced became available in 1981 designated the Series 200F Advanced powered by the -17A engines and featured a strengthened fuselage structure, an 11 ft 2 in (3.40 m) by 7 ft 2 in (2.18 m) forward main deck freight door, and a windowless cabin. This was the last production variant of the 727 to be developed by Boeing, and 15 aircraft were built, all for Federal Express; the last 727 aircraft completed by Boeing was a 727-200F Advanced. ; Super 27 Speed was increased by 50 mph (80 km/h) by replacement of the two side engines with the JT8D-217 or the JT8D-219, which are also found on many MD-80s, along with the addition of hush kits to the center engine. were added to some of these aircraft to increase fuel efficiency. This modification was originally developed by Valsan Partners, but was later marketed by Quiet Wing Technologies in Redmond, Washington. ; Boeing C-22C : A single 727-212 aircraft was operated by the USAF. Operators[] was the last 727 scheduled passenger airline Main article: Commercial operators[] is the largest 727 operator with six As of July 2018update, there were 44 Boeing 727s (2 Boeing 727-100s and 42 727-200s) in commercial operation with 23 airlines. Only still operated 2 Boeing 727-200s in passenger service (plus one freighter); all other remaining Boeing 727s in commercial service were used for cargo. Most airlines had small numbers, but these operated five or more aircraft: Iran Aseman made its last scheduled passenger flight on 13 January 2019. * (6) * (5) * use 2 modified ex DHL 727-200 freighters, operated by 2 Excel Aviation, equipped with oil dispersal tanks and spray booms to deal with oil spills. Government, military, and other operators[] 727 In addition, the 727 has seen sporadic government use, having flown for the , , Mexican, New Zealand, and air forces, among the small group of government agencies that have used it. The United States military used the 727 as a military transport, designated as the C-22. ; * - Three being acquired from ; * (1) ; * (Transporte Aereo Militar) (1) ; * (1) ; * * (2) ; * (4) ; * (2) ; * (3) ; * , Salah Aldin (1) ; * (5) * (4) Private aircraft[] A number of 727s have been outfitted for use as private aircraft, especially since the early 1990s when major airlines began to eliminate older 727-100 models from their fleet. traveled in a former American Airlines 727-100 with dining room, bedroom and shower facilities before upgrading to a larger in 2009; acquired a 727-100 for private use in 2005. Accidents and incidents[] Main article: As of July 2015update, a total of 336 incidents involving 727s had occurred, including 118 resulting in a total of 4,209 fatalities. The 727 has also been in 178 involving 345 fatalities. Orders and deliveries[] Source: Data from Boeing, through the end of production '''Boeing 727 orders and deliveries (cumulative, by year):' Orders Deliveries Model summary[]